1. Field of the Invention
This invention relates to a power source control system for electronic machines, and more particularly to a control system according to which the power consumption of electronic machines, such as a portable type of battery-driven small sized electronic calculator, handy typewriter, etc. is extremely minimized, wherein an electronic circuit can be driven without a battery.
2. Description of the Prior Art
In conventional electronic calculators, once a power switch is turned on, power is continually consumed during the whole time until the switch is turned off. Also, in the portable type of battery-driven small sized electronic calculators, almost all of the power is consumed in display elements such as electroluminescent diodes. Therefore, there has been provided such an arrangement that the display elements are deenergized by a timer after a predetermined time has elapsed. However, this does not provide any decisive solution to the power saving problem. Actually, the time used for key operation in the use of a calculator is short, and the remaining time is spent mostly for arranging papers, preparing writing utensils, planning where to start the process, or answering the phone. Further, the smaller the number of parts, the better.